.\"	$NetBSD: shutdown.2,v 1.17 2004/05/13 10:20:58 wiz Exp $
.\"
.\" Copyright (c) 1983, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)shutdown.2	8.1 (Berkeley) 6/4/93
.\"
.Dd August 18, 2002
.Dt SHUTDOWN 2
.Os
.Sh NAME
.Nm shutdown
.Nd shut down part of a full-duplex connection
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/socket.h
.Ft int
.Fn shutdown "int s" "int how"
.Sh DESCRIPTION
The
.Fn shutdown
call causes all or part of a full-duplex connection on
the socket associated with
.Fa s
to be shut down.
The
.Fa how
argument specifies which part of the connection will be shut down.
Permissible values are:
.Bl -tag -width SHUT_RDWRXX -offset indent
.It SHUT_RD
further receives will be disallowed.
.It SHUT_WR
further sends will be disallowed.
.It SHUT_RDWR
further sends and receives will be disallowed.
.El
.Sh RETURN VALUES
A 0 is returned if the call succeeds, \-1 if it fails.
.Sh ERRORS
The call succeeds unless:
.Bl -tag -width Er
.It Bq Er EBADF
.Fa s
is not a valid descriptor.
.It Bq Er EINVAL
The
.Fa how
argument is invalid.
.It Bq Er ENOTCONN
The specified socket is not connected.
.It Bq Er ENOTSOCK
.Fa s
is a file, not a socket.
.El
.Sh SEE ALSO
.Xr connect 2 ,
.Xr socket 2
.Sh HISTORY
The
.Fn shutdown
function call appeared in
.Bx 4.2 .
The
.Fa how
arguments used to be simply 0, 1, and 2, but now have named values
as specified by
.St -xpg4 .
